| Today we have witnessed the proliferation of wireless networks including wireless local area networks (WLANs), wireless mobile ad hoc networks (MANETs), wireless sensor networks (WSNs), wireless mesh networks (WMNs), hybrid wireless networks, heterogeneous wireless networks, and so on. There is no doubt that wireless networks have become and will continue to be an important part of our daily life. Besides, nowadays the Internet's phenomenal growth has triggered great increase on demands for broadband services. As a part of the Internet, wireless Internet is hence expected to provide applications with various quality of service (QoS). Unfortunately, however, the current wireless networks cannot satisfy the requirements. In this dissertation, we both theoretically analyze the capacity of different kinds of wireless networks and design practical cross-layer networking protocols to improve the throughput in wireless networks.;For the capacity analysis part, we investigate the capacity of many different types of wireless networks. First, we study the connectivity and capacity of wireless networks using directional antennas. Then, we explore the capacity and delay in hybrid wireless networks employing an efficient resource allocation strategy. We also investigate the capacity of heterogeneous wireless networks with very general network settings. Moreover, we investigate the trade-offs among capacity, delay, and mobility in wireless networks.;Inspired by the theoretical analysis, we also propose real cross-layer networking protocols for wireless networks. Known as Wi-Fi technology, IEEE 802.11 standards have been widely used in wireless networks. We first analyze the performance of IEEE 802.11 MAC in multi-hop ad hoc networks by proposing a new Markov chain model. Then, we design a MAC protocol for mobile ad hoc networks using directional antennas along with some further improvements. Besides, we also propose a coupled MAC and routing cross-layer design for ad hoc networks with power control. Furthermore, we look into the use of multiple channels in wireless mesh networks by carrying out real experiments on our testbeds, and provide some guidelines for using multi-channel in WMNs. |
